Footwell heater blower, Left. Porsche 911 1983-89  ❭  91162404

Coolant pump auxiliary heating. 

Fits:
Porsche 955 Cayenne S / Cayenne turbo - 2003 to 2006
Porsche 957 Cayenne - 2007 to 2010 (Option codes 7VE, 7VL, 9AH, D5X, D5V, D5Z, 9M5, 9AH)
Porsche 958 Cayenne - 2010 to 2017 (Option Codes 9M1, 9M5, 9M9)

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Diagram ref no 24

Auxiliary Coolant Pump for Heating System

The auxiliary coolant pump for the Porsche 955, 957 and 958 Cayenne is a secondary electric water pump designed to support coolant circulation through the vehicle’s heating system. This pump ensures consistent coolant flow to the heater matrix, improving cabin heating performance and maintaining balanced engine temperature control.  This is a key component of the cooling and climate system, particularly in colder conditions and during idle operation.

Fits:

• Porsche 957 Cayenne 3.0L Diesel 2007-10
• Porsche 957 Cayenne 3.6L 2007-10
• Porsche 957 Cayenne S / GTS 4.8L 2007-10
• Porsche 957 Cayenne Turbo / Turbo S 4.8L 2007-10

• Porsche 958 Cayenne V6 3.6L Petrol (300Hp) 2010-17
• Porsche 958 Cayenne V6 3.0L Diesel (245Hp) 2010-17
• Porsche 958 Cayenne S V6 3.0L Hybrid (380Hp) 2010-17
• Porsche 958 Cayenne S V8 4.8L Petrol (400Hp) 2010-17
• Porsche 958 Cayenne S V8 4.2L Diesel (382Hp) 2010-17
• Porsche 958 Cayenne GTS V8 4.8L Petrol (400Hp) 2010-17
• Porsche 958 Cayenne Turbo V8 4.8L Petrol (500Hp) 2010-17
• Porsche 958 Cayenne Turbo S V8 4.8L Petrol (550Hp) 2010-17

What the Auxiliary Coolant Pump Does

Unlike the main engine-driven water pump, the auxiliary coolant pump operates electrically and assists with circulating coolant when required. It is responsible for:

• Supplying hot coolant to the cabin heater core
• Supporting even heat distribution inside the vehicle
• Maintaining coolant flow at idle or low engine speeds
• Assisting with temperature regulation in complex cooling systems
• Improving warm-up efficiency

In Porsche Cayenne models equipped with advanced climate control systems, the auxiliary pump plays an important role in ensuring reliable heating performance.

Why Auxiliary Coolant Pumps Fail

Over time, the auxiliary coolant pump can fail due to:

• Electrical motor wear
• Internal bearing degradation
• Coolant contamination
• Heat cycling within the engine bay
• Age-related plastic housing fatigue
• Corrosion from coolant exposure

Because the pump operates electrically, failure may occur suddenly or gradually.

Common symptoms of a failing auxiliary coolant pump include:

• Weak or inconsistent cabin heating
• Heater blowing cold air at idle
• Coolant circulation fault codes
• Check engine or cooling system warning lights
• Unusual noise from the cooling system
• Coolant leaks around the pump housing

When You Should Replace the Auxiliary Coolant Pump

You should consider replacing the auxiliary coolant pump if:

• Cabin heating performance becomes inconsistent
• The vehicle struggles to maintain warm air at idle
• Diagnostic fault codes indicate coolant circulation issues
• The pump becomes noisy or stops functioning
• You are servicing other cooling system components
• The vehicle has high mileage and original cooling parts

Replacing the pump proactively helps maintain reliable heating performance and prevents strain on other cooling system components.

At Design911, we supply high-quality auxiliary coolant pumps engineered to meet OEM specifications. Designed for durability and reliable performance, this pump restores proper coolant circulation and heating efficiency.

Maintaining your Cayenne’s cooling and heating system is essential for both comfort and long-term engine reliability.

Key Benefits at a Glance

• Direct replacement auxiliary coolant pump
• Restores cabin heating efficiency
• Maintains proper coolant circulation
• Reduces risk of overheating or heater malfunction
• Suitable for Porsche 955, 957 and 958 Cayenne
• Ideal for repair or preventative cooling system maintenance